The present invention relates to a marine vessel for transporting a military vehicle, more particularly, to a planing hull that carries a light armored vehicle during the first phase of an amphibious assault in which the longitudinal center of gravity of the combined hull and vehicle can be varied as a function of the water speed. More particularly, the present invention relates to a method for transitioning the hydrodynamic hump of a marine vessel having a planing hull to obtain maximum speed with minimum power.
In amphibious warfare, many different kinds of marine vessels, usually referred to as landing craft, have been employed for the purpose of transporting cargo and personnel from a mother ship or base to a landing upon a beach. A wide variety of vehicles, both wheeled and with tracks, which were necessary to carry out the designated mission have been transported by these landing craft to positions upon a beach. Such cargo landing craft are rather ponderous in structure and move at slow speeds through the water. Thus, a rather long period of time is required to travel from either a base or mother ship to the beach landing area. Since the mother ship may be anchored about 20 miles from the landing beach, the long time required to make the trip from the mother ship to the beach is undesirable and may even cause discomfort and illness among the personnel.
It was then considered that marine vessels each carrying a single vehicle, such as a light armored vehicle, might be utilized, particularly in the first phase of an amphibious assault. The concept of using a planing hull that carries a single vehicle has thus been explored and various such hulls have been investigated. Such a marine vessel for a single military vehicle, or a planing hull, should be simple in construction, easy to operate, provide quick loading and unloading of the vehicle and be capable of stable travel through the water when loaded at speeds of up to 20 knots.
It is therefore the principal object of the present invention to provide a novel and improved marine vessel for transporting a military vehicle in an amphibious operation.
It is another object of the present invention to provide such a marine vessel wherein the longitudinal center of gravity of such a vessel loaded with a vehicle can be controlled as a function of the vessel water speed.
It is a further object of the present invention to provide such a marine vessel which has retractable wheels and which can be towed up on the beach to function as a fuel supply depot, a fuel pumping station, a source of power, maintenance or repair facility, or an armored command post.
It is an additional object of the present invention to provide such a marine vessel which is simple in construction, easy to operate and maintain and which can be loaded or unloaded with a minimum of effort and without exposing the personnel manning the vehicle to enemy fire.
According to one aspect of the present invention, a method for transitioning the hydrodynamic hump of the marine vessel having a planing hull to obtain maximum speed with minimum power comprises the steps of positioning movable ballast at a predetermined aft first position in the vessel to obtain a first vessel trim angle at a predetermined vessel water speed less than the hump speed of the vessel; and shifting the ballast forwardly in the vessel to change the longitudinal center of gravity of the vessel in dependence on the vessel water speed as the vessel water speed approaches the hump speed of the vessel so as to obtain a second vessel trim angle for passage of the vessel through the hump speed to the running speed of the vessel.
According to another aspect of the present invention, a marine vessel for transporting a military vehicle in an amphibious assault may comprise a hull having means thereon connectible to a vehicle on the deck of the hull for securing the vehicle in position thereon. Means are also provided for moving the secured vehicle fore and aft with respect to the water speed of the vessel in order to vary longitudinally the center of gravity. The cable from the recovery winch on the front of the vehicle is passed under a deck fairlead to be attached to a cable anchor having a hydraulic release so that winding of the winch will move the vehicle aft against a torsion spring or hydraulic structure which is capable of moving the vehicle fore when the winch is unwound.